Traveling wave tubes (TWTs) are a common feature of most communication satellites. Multiple TWTs are used on spacecraft and generally an individual power supply, known as an electronic power condiditioner (EPC), is associated with each TWT. The EPC delivers the necessary bias voltages and currents to the TWT.
A dual EPC which allows one of two TWTs to be independently turned on and off, turns on and off the anode voltage to the respective TWT. In the prior art, this is done by referencing an anode drive circuit to the cathode potential.
In the prior art, the anode drive circuits are referenced to a cathode voltage that is common to both TWTs. In this configuration it is possible to vary the anode voltage between its normal operating voltage and the cathode voltage thereby turning off the respective TWT. A large anode drive voltage is required due to the large voltage difference between the anode voltage and the cathode voltage.
The prior art circuit is overly complex, which ultimately results in lowered operating efficiency. There is a need for an anode voltage control circuit that allows independent control of each TWT and improves the operating efficiency of an EPC.